Surface energy engineering for tunable wettability through controlled synthesis of MoS2

Anand P.S. Gaur, Satyaprakash Sahoo*, Majid Ahmadi, Saroj P. Dash, Maxime J.F. Guinel, Ram S. Katiyar*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

173 Citations (Scopus)

Abstract

MoS2 is an important member of the transition metal dichalcogenides that is emerging as a potential 2D atomically thin layered material for low power electronic and optoelectronic applications. However, for MoS2 a critical fundamental question of significant importance is how the surface energy and hence the wettability is altered at the nanoscale in particular, the role of crystallinity and orientation. This work reports on the synthesis of large area MoS2 thin films on insulating substrates (SiO2/Si and Al2O3) with different surface morphology via vapor phase deposition by varying the growth temperatures. The samples were examined using transmission electron microscopy and Raman spectroscopy. From contact angle measurements, it is possible to correlate the wettability with crystallinity at the nanoscale. The specific surface energy for few layers MoS2 is estimated to be about 46.5 mJ/m2. Moreover a layer thickness-dependent wettability study suggests that the lower the thickness is, the higher the contact angle will be. Our results shed light on the MoS2-water interaction that is important for the development of devices based on MoS2 coated surfaces for microfluidic applications. © 2014 American Chemical Society.
Original languageEnglish
Pages (from-to)4314-4321
Number of pages8
JournalNano Letters
Volume14
Issue number8
DOIs
Publication statusPublished - 13-Aug-2014

Keywords

  • Neumanns method
  • chemical vapor deposition
  • contact angle
  • defects
  • wettability

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